Connecting rod



ay 12, 1936. R. CHILTON 2,040,465

CONNECTING ROD Filed June 1, 1934' 2 Sheets-Sheet 1 fig, 1. 20

INVENTOR Roland (/rilton Y B 4 a ATTORNEY Q May 12, 1936. R CHILTON 2,040,465

CONNECTING ROD Filed June 1, 1934 2 Sheets-Sheet 2 AILTORNE Patented May 12, 1936 UNITED STATES PATENT OFFICE CONNECTING ROD York Application June 1, 1934, Serial No. 728,481

8 Claims.

This invention relates to connecting rods for radial engines and comprises a new and improved form of the slipper type rod.

The well known master rod and link rod construction for radial engines has offset knuckle pins which follow elliptical paths which introduce variations in the angularities of the different rods and upset the engine balance and the piston travel relationships. The slipper design, wherein each rod engages an annular track in a crankpin-bearing member, gives uniform motion of the pistons.

In order to guard against binding of the slippers in their tracks, a substantial arc of embracement for each slipper is essential and the required circumferential slipper length is greater than the space available when several slippers of simple rectangular form are disposed in a common track. The prior art shows various double track schemes for obtaining a greater efiective arc of embracement, and diagonally disposed slippers have been proposed for the same purpose. The double tracks are relatively expensive to produce and tend to weaken the 'bearin'g'member as compared to the simpler single track. The diagonally disposed slipper fails to guide the rod adequately against tipping at right angles to the long diagonal axis of the slipper.

Objects of the present invention are to provide a simplified structure which will overcome these limitations as will be clear from the following description.

In the drawings:

Fig. 1 is a section through the crankpin axis showing one rod in complete section;

Fig. 2 is an isometric detail view showing the form of slipper;

Fig. 3 is an end view with certain parts in section; and

Fig. 4 is a developed diagram showing the slipper disposition. I

In the figures, l0 designates the crankpin bearing member comprising similar halves opposed on either side of the transverse midplane of the assembly. A crankpin l2 has been shown as integral with crankshaft webs M in which case the bearing members H! are split in the plane of the crankpin axis and secured together by bolts I6. Each of the members I0 is provided with an annular groove l8 in which are disposed the several slippers 20 of rods 22.

The permissible annular width of each main slipper portion 20 is determined by the number of rods and by the clearance necessary to permit of relative motion. With six rods, for ex-'- ample, the limited arc of embracement is insufficient to insure against binding of the slippers inthe tracks, and according to this invention each slipper is provided, on one side, with relatively narrow guiding extensions 24 and the rods are assembled with these extensions on alternate sides as indicated clearly in Fig. 4. It will be obvious that the annular length of slipper in the case of six rods is only one-half of that available with three rods and that by the novel disposition of this invention the length available for the guiding extensions is that obtainable in a conventional three rod construction, although six rods are actually accommodated.

It will be understood that the main portion 20 of the slippers are of symmetrical disposition so that the loads on the extensions 24 are merely those incident to guiding the rods circumferentially. These light loads may generate a slight twisting tendency on the rod for which a relatively wide guiding surface 26 is accordingly provided in the rod shank, this surface engaging the opposed outer faces 28 of the bearing members Ill.

The bearing members III are provided with a bushing 30 which runs on the crankpin l2 and behind this bushing there are provided, in the members [0, a plurality of oil holes 32, in which are engaged small valves 34, which are lifted slightly off their seats whenever the associated oil hole is covered by one of the slippers 20. Whenever the oil hole passes into the space between adjacent slippers, the associated valve 34 closes by the action of centrifugal force and oil pressure, thus preventing loss of oil when theholes are uncovered. It will be clear that when the valve is on its seat the end protrudes slightly beyond the surface in the track to permit the automatic actuation from the slippers as just described. By this means it is possible toprovide for full pressure lubrication to the slippers without excessive loss of oil, which occurs when holes subject to oil pressure are left open, as in the spaces between the slippers. The interior of the crankpin I2 is subject to oil pressure in the usual way and the oil flows by way of the oil holes 36 in the crankpin and holes 38 in the bearing member ID, to suitable grooves 40 which connect to the valves.

It will be seen that by the novel form of slipper here disclosed a long are of guiding embracement is provided in a simple single track bearing member permitting twice the arc of guiding slipper than would be possible in conventional single track construction. Also, the slippers are in rec- What is claimed is: V 1. Aradial engine connecting rod system including a pair of bearing members having opposed and similar annular tracks, and a plurality ,of rods each having a main slipper engaging both tracks and a guide slipper extending axially and circumferentially from the main slipper, each rod having its guiding slipper engaged in one said track, the guideslippers of rods adjacent thereto being engaged in the opposite track, each said guide slipper having an arc of track embracement, substantially twice as great as the arc of track embracement of each main slipper, and overlapping the main slipper of an adjacent rod.

2. A slipper rod system for use with a crankpin having opposed annular tracks, each rodcomprising a shank, a main slipper portioncarried by said shank and substantially coaxial with the rod, said portion engaging both saidtracks, and auxiliary guiding slipper portions springing from,

saidmain portion and engaging one said-track, said auxiliary slipper portions having a greater are of bearing contact than said main slipper portion, and being. axially offset therefrom, theadjacent rods having their guiding slipper. portions in opposite tracks, the guidinglslipper portions of each rod overlapping the main slipper portions of adjacent rods.

3. In a rod system for a radial'engine, a pair of annular opposed tracks, a plurality of similar rods having bearing slippers engaging said tracks,

and guiding slipper portions extending axially andcircurnferentially from each said slipper, the guiding slipper portion of each rod engaging one said track, the guide slippers of rods adjacent thereto being engaged in the. opposite track, each said guide slipperg overlapping the bearin slippers.

of adjacent. rods;

4; In a rodsystem for a radialengine; a pair of opposed.bearing members, having opposite, similar, annular tracks'therein; and. aiplurality of similar connecting rods. each having-a main bearinglslipper engaging bothsaid tracks; the midportion of. said slipper being substantially coaxial with the rod axis, and said slipper being substantially symmetrical on each side of; the plane of rod rotation, and anauxiliary guide slipperv extending axially and circumferentially =-from said'main slipper, said guide s1ipper,-ha.ving a greater are of track embracement than said,

'main slipper, each said guide slipper engaging within one said track, and guide slippers adjacent thereto engaging Within the other said track.

5. In a rod system for a radial engine; a pair of opposed bearing members, having opposite, similar, annular tracks therein; and a plurality of similar connecting rods each having a main bearing slipper engaging both said tracks, the midportion of said slipper being substantially coaxial with the rod axis and said slipper being substantially symmetricalon each side of the plane of rod rotation, and an auxiliary guide slipper extending axially and circumferentially from said main slipper, said guide slipper having a greater arc of track embracement than said main slipper, each said guide slipper engaging within one said track, and guide slippers adjacent thereto engagingwithin the other said track, the guide slippers of any one rod overlapping the main slippers of adjacent rods.

6. A slipper rod system for a radial engine comprising a member having opposed annular tracksand rods each having a main slipper engaging each of said tracks, each of said rods having guiding slipper portions extending in circum- I ferential symmetry from one. end only of said main portion and engaging only one of said annular tracks, the adjacent rods of the system having; their guiding slipper portions'engaged in opposite tracks and each overlapping the next adjacent main slippers. I e e v 7. A rod system for a radial engine each rod including main and auxiliary slipper portions having outer and inner bearing surfaces, the outer surfaces of both said main and auxiliary portions having the same radius, and the inner surfaces of both saidmainand auxiliary portions having.

the sameradiu's, the auxiliary portions extending in circumferential symmetry from the main portion on one side only of the plane of rotation, and

each guide slipper overlapping the main slipper of a next adjacent rod.

8. A-radial engine connecting rod systemin-f cluding, in combination, a pair of bearing members having opposed similar annular tracks, a.

main symmetrical slipper on each rodengaging;

both tracks, and a guide slipper formed as an extension ofeach main slipper, said guide slipper being axially spaced from the plane of rodrota tion, and extending circumferentially beyond both ends of its associated main slipper, the guideslipperson adjacent rods being assembled in stag.- gered relation in said bearing members, said main slippers each having a circumferential dimension substantially equal to the track circumference divided. by the number of rods, and each said auxiliaryslipper'having a circumferential dimension substantially equal to twice the-circumferentialdimensionof each said main slipper.

ROLAND CHILTQhL; 

